Process for echo suppression with adaptive fir filters

US6493448B1 · kind B1 · utility

Assignee

• ALCATEL · FR

Inventors

• Armin Mann · Sachsenheim, DE
• Hans Jurgen Matt · Waiblingen, DE
• Michael D. Walker · San Francisco, US

Key dates

• Filing date: Jan 15, 1999
• Grant date: Dec 10, 2002
• Expiry date: Jan 15, 2019

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B3/23
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A process for suppressing total echoes comprising a plurality of partial echoes in telecommunications (TK) equipment such as terminals, transmission systems, or switching equipment by means of adaptive FIR (=Finite Impulse Response) filters that simulate the total echo and subtract it from the echo-affected useful signal transmitted to the respective TK equipment, whereby n partial FIR filters are provided, which respectively simulate a partial echo, is characterized in that m parallel, mutually independent TK channels are provided with an echo suppression function and that for this purpose a variable sub-quantity of the partial FIR filters is assigned to a TK channel to be operated, respectively, as required depending on the number of partial echoes and the size of the occurring delay times between signal and echo. This permits effective echo suppression without significant memory space and computational effort even for a large number of m parallel, mutually independent TK channels, such as must be processed in switching equipment or gateways.